In this particular technical area, there are known milling tools that have a core. Sectors of abrasive material are provided on the core, typically arranged at a regular angular pitch around the core. When such tools are used, the heat produced in the milling operation as a result of the contact between the abrasive sectors and the surfaces of the work piece must be dissipated adequately. Typically, heat dissipation is achieved by conveying cooling fluids to the areas being machined.
According to a known solution, the core of the tool is provided with a plurality of holes extending radially from the outer casing of the core in the direction of its main axis and also positioned in the portions of the core located between pairs of abrasive elements adjacent to each other. With these holes so configured, the cooling fluid is delivered from the inside of the core into the length occupied by the abrasive elements so as to enhance the cooling effect.
The conventional solution has some limitations, however, due mainly to the fact that the presence of the holes in the core creates structural discontinuities in the core. Such discontinuities generate localized increases in the state of stress induced in the tool by machining forces. These stresses may compromise the tool structurally, typically generating fatigue fractures. Moreover, the presence of a plurality of holes for the cooling fluid to pass through introduces a discontinuity in the cooling of the tool along the core, this being greatest at the holes but characterized by thermal gradients in the areas between adjacent holes.